Apparatus for driving a document through an encoder station

Abstract

A document encoding system transmits an incoming document at a high transport speed. When the document is received at an encoding station it is first stopped and registered and then retransmitted for encoding at a relatively low speed, the exact value being dependent on whether MICR or OCR encoding is used. After characters are encoded on the document the trailing edge is detected and the document is caused to accelerate to the high transport speed where it is transmitted for further processing. In a second alternative embodiment, information relating to character field positions is used to transmit the document at the relatively low speed when encoding and at a heightened speed when otherwise in the encoding station but not encoding. In a third alternative embodiment, the document is received by the encoding station on the fly at the high transport speed. It is advanced at that speed until decelerated to the relatively low speed at the first encoding position. When an end-of-encode signal is given the document is accelerated to the high transport speed and exits the station.

What is claimed is: 
     
       1. A system for driving a document through an encoder apparatus having means for generating signals indicative of the characters to be encoded at predetermined character positions on said document and having an encoder station therein for prining said characters at said predetermined character positions, said document drive system comprising: first drive means for transporting said document at a first relatively high predetermined document transport speed into and out of said encoder apparatus;   second drive means within said encoder apparatus for receiving said document from said first drive means and driving said document past said encoder station and toward said first drive means which again receives and exits said document from said encoder apparatus; and   means for controlling the operation of said second drive means for increasing the throughput of said encoder apparatus, said control means including: means at the input of said encoder apparatus for receiving said document from said first drive means and for registering said document at a predetermined position as it enters said encoder apparatus;   means coupled to said second drive means for transporting said document from said predetermined position at the entrance of said encoder apparatus toward said encoder station and for driving at least that portion of said document having said predetermined character positions in which characters are to be encoded past said encoder station at a relatively constant, relatively slow predetermined encoding speed until the last character to be encoded on said document is printed thereon;   means for rapidly accelerating said document from said predetermined encoding speed toward said first relatively high predetermined document transport speed of said first drive means for exiting said document from said encoder apparatus when the last character to be encoded on said document has been printed thereon; and   means responsive to the exit of said document from said encoder apparatus for restoring said second drive means to await the arrival of the next successive document at the input of said encoder apparatus for transporting said next successive document toward said encoder station.     
     
     
       2. The document drive system of claim 1 wherein said second drive means includes roller means for contacting and driving said documents within said encoder apparatus and a DC servo motor means for driving said roller means. 
     
     
       3. The document drive system of claim 2 wherein said means at the input of said encoder apparatus for receiving said document includes means for stopping and registering said document at said predetermined position as it enters said encoder apparatus; wherein said means for transporting said document from said predetermined positon toward said encoder station includes means for initially accelerating said document from said stopped position to said relatively constant predetermined encoding speed; and wherein said control means further includes means for monitoring the speed and position of said document relative to said encoder station and means for maintaining said predetermined encoding speed relatively constant until the last character to be encoded on said document has been printed thereon. 
     
     
       4. The document drive system of claim 3 wherein said control means further includes means responsive to the exit of said document from said encoder apparatus for electrically braking said DC servo motor means to a stopped position to enable said document receiving means to await the arrival of the next successive document at the input of said encoder apparatus. 
     
     
       5. The document drive system of claim 4 wherein said means for monitoring the speed and position of said document includes a slotted disk coupled to said DC servo motor means, photoelectric means associated with said slotted disk for generating electrical timing pulses indicative of the actual speed of said DC servo motor means, and means for shaping said electrical timing pulses; and wherein said means for maintaining said predetermined encoding speed relatively constant includes means for generating a reference signal indicative of the nature of the characters being encoded on said document and the desired speed necessary for the proper spacing of said characters, a frequency/phaase discriminator circuit means for establishing a phase-locked loop for comparing the actual speed with the desired speed and for generating a signal indicative thereof, means for supplying said reference signal to said frequency/phase discriminator circuit means, means for supplying said shaped electrical timing pulses to said frequency/phase discriminator circuit means, and means for coupling the output of said frequency/phase discriminator means to said second drive means for varying the current supplied to said DC servo motor means to maintain said relatively constant predetermined document encoding speed. 
     
     
       6. The document drive system of claim 4 wherein said means for electrically braking said second drive means includes means for generating a signal indicative of the exit of said document from said encoder apparatus; means for electrically reversing the current supplied to said DC servo motor means for electrically braking said motor means by attempting to drive it in the opposite direction; and means responsive to said shaped electrical timing pulses for sensing when said motor speed has reached a predetermined low speed for removing the drive current from said DC servo motor means before said DC servo motor means actually begins to run in the opposite direction thereby allowing said DC servo motor means to come to said stopped position. 
     
     
       7. The document drive system of claim 2 wherein said means at the input of said encoder apparatus for receiving said document includes means for stopping and registering said document at said predetermined position as it enters said encoder apparatus; wherein said control means further includes meams for generating a signal indicative of the first character position on said document in which a character is to be encoded, means for monitoring the speed and position of said document with respect to said encoder station, and means for determining when particular character positions on said document are at a predetermined distance from said encoder station; and   wherein said means for transporting said document from said predetermined registration position toward said encoder station includes: means for rapidly accelerating said document from said stopped position and responsive to said determining means for continuing to accelerate said document until said first character position in which a character is to be encoded is a predetermined distance from said encoder station;   means responsive to a determination that said first character position in which a character is to be encoded is said predetermind distance away from said encoder station for decelerating said document until a relatively low predetermined encoding speed has been attained; and   phase-locked loop circuit means resonsive to said document speed having been decelerated to said predetermined encoding speed for maintaining said predetermined encoding speed relatively constant until the last character to be encoded on said document has been printed thereon.     
     
     
       8. The document drive system of claim 7 wherein said decelerating means further included means responsive to the exit of said document from said encoder apparatus for reversing the current supplied to said DC servo motor means and electrically braking said DC servo motor means to a stopped position to enable said document receiving means to await the arrival of the next successive document at the input of said encoder apparatus. 
     
     
       9. The document drive system of claim 8 wherein said means for monitoring the speed and position of said document with respect to said encoder station includes a slotted disk coupled to said DC servo motor means for rotation therewith, and photoelectric means associated with said slotted disk for generating electrical timing pulses indicative of the actual speed of said DC servo motor means; wherein said phase-locked loop circuit means includes means for generating a reference signal indicative of the desired speed necessary for the proper spacing of said characters to be encoded on said document, a frequency/phase discriminator circuit means for comparing the actual speed of said DC servo motor with said desired speed and for generating an output control signal indicative thereof, means for supplying said reference signal to said frequency/phase discriminator circuit means, means for supplying said electrical timing pulses indicative of the actual speed of said DC servo motor means to said frequency/phase discriminator circuit means, and means responsive to said output control signal for controlling said second drive means for varying the current supplied to said DC servo motor means to maintain said predetermined document encoding speed relatively constant.   
     
     
       10. The document drive system of claim 9 wherein said means for electrically braking said DC servo motor means includes means for generating a signal indicative of the exit of said document from said encoder apparatus; means for electrically reversing the current supplied to said DC servo motor means for electrically braking said motor by attempting to drive it in the opposite direction; and   means responsive to said electrical timing pulses for sensing when said motor speed has reached a predetermined low speed for removing the drive current from said DC servo motor means before said DC servo motor means actually begins to run in the opposite direction thereby allowing said DC servo motor means to come to said stopped position; and   wherein said control means further includes means responsive to the exit of said document from said encoder apparatus for disabling said phase-locked loop circuit means to allow said electrical braking means to decelerate said DC servo motor to said predetermind low speed for stopping said DC servo motor.   
     
     
       11. The document drive system of claim 2 wherein said means at the input of said encoder means for receiving said document includes means for receiving said document on-the-fly from said first drive means and for registering said document at said predetermined positiion as it enters said encoder apparatus; wherein said control means further includes means for generating a signal indicative of the first character position on said document in which a character is to be encoded, means for monitoring the speed and position of said document with respect to said encoder station, and means for determiniing when said first character position is a predetermined distance from said encoder station; and   wherein said means for transporting said document from said predetermined registration position toward said encoder station includes means responsive to a determination that said fist character position in which a character is to be encoded is said predetermind distance away from said encoder station for decelerating said document until a relatively low predetermined encoding speed has been attained, and phase-locked loop circuit means responsive to said document having been decelerated to said predetermined encoding speed for maintaining said predetermined encoding speed relatively constant until the last character to be encoded on said document has been printed thereon.   
     
     
       12. The document drive system of claim 11 wherein said means responsive to the exit of said document from said encoder apparartus for restoring said second drive means to await the arrival of the next successive document at the input of said encoder apparatus includes means for sensing the actual speed of said document and for generating signals indicative thereof, and logic means responsive to said signals indicatvie of the actual speed of said document for determining when said document has been accelerated to said first relatively high predetermined document transport speed thereby enabling said second drive means to await the arrival of the next successive document at the input of said encoder apparatus for receiving said document on-the-fly from said first drive means at said first relatively high predetermined document transport speed. 
     
     
       13. The document drive system of claim 12 wherein said means for decelerating said document until a relatively low predetermined encoding speed has been attained includes means for generating a deceleration initiation signal when said first character position in which a character is to be encoded is said predetermined distance away from said encoder station, means responsive to said deceleration initiation signal for reversing the supply of drive current to said DC servo motor for electrically braking said motor by attempting to drive it in the opposite direction thereby decelerating said document until said relatively low predetermined encoding speed has been attained, and means responsive to the attainment of said relatively low predetermined encoding speed for enabling said phase-locked loop circuit means to assume the speed control of said DC servo motor until the last character to be encoded on said document has been printed thereon. 
     
     
       14. A document encoding system comprising: means for encoding characters on a document;   drive means for driving said document into and out of said encoding means;   means for transporting said document at a relatively high document transport speed into and out of said drive means;   means for monitoring the location of particular encoding positions on said document with respect to said encoding means;   means responsive to said monitoring means and to information as to the characters to be encoded in the various encoding positions on said document for enabling said encoding means to print a desired character in its proper encoding position on said document; and   control means for controlling said drive means to drive said document by said encoding means at a relatively slow encoding speed while said characters are being encoded on said document and for driving said document by said encoding means at a mediate speed, greater than said relatively low speed, prior to the start of encoding and after the encoding operation is completed thereby increasing the throughput of said document encoder system.   
     
     
       15. The document encoder system of claim 14 wherein said control means further comprises: means for stopping and registering said document prior to engagement by said drive means;   means responsive to the registration of said document for enabling said drive means to accelerate said document toward said encoding means at said mediate speed;   means responsive to the first encoding position on said document in which a character is to be encoded being a predetermined distance from said encoding means for decelerating said document;   means for selecting a first value of said relatively low encoding speed that corresponds to the encoding of MICR characters on said document and for selecting a second value of said relatively low encoding speed that corresponds to the encoding of OCR characters on said document;   means responsive to said selected value of said relatively low encoding speeds for establishing and maintaining said speed until all of the desired characters have been encoded on said document;   means for accelerating said document to said relatively high transport speed for exiting said document from said encoding means; and   means for electrically braking said drive means to a stop position to await the arrival of the next document at the input of said encoder station.   
     
     
       16. The document encoder system of claim 14 wherein said control means further comprises: means for enabling said document to enter said encoding means at said relatively high transport speed;   means responsive to the first encoding position which is to be encoded on said document being a predetermined distance from said encoding means for decelerating said document;   means for selecting a first value of said relatively low encoding speed that corresponds to the encoding of MICR characters on said document and for selecting a second value of said relatively low encoding speed that corresponds to the encoding of OCR characters on said document;   means responsive to said selecting means for establishing and maintaining said relatively low encoding speed while said document is being encoded by said encoding means; and   means responsive the termination of encoding on said document for rapidly accelerating said document out of said encoding means for engagement by said transport means thereby increasing the throughput of said document encoder system.